Bug 1662809 - don't copy key-value pairs from blocklist entries during parsing; r=aosmond

Instead of splitting the entire entry into an `nsTArray`, we can use
`nsTSubstring::Split` to provide dependent strings into the entry.  We copy
the actual keys and values later, so this should be perfectly safe.

Depends on D89168

Differential Revision: https://phabricator.services.mozilla.com/D89169

widget/GfxInfoBase.cpp

@@ -490,19 +490,15 @@ static bool BlocklistEntryToDriverInfo(nsCString& aBlocklistEntry,
         << GfxInfoBase::GetApplicationVersion().get();
   }
 
-  nsTArray<nsCString> keyValues;
-  ParseString(aBlocklistEntry, '\t', keyValues);
-
   aDriverInfo.mRuleId = "FEATURE_FAILURE_DL_BLOCKLIST_NO_ID"_ns;
 
-  for (uint32_t i = 0; i < keyValues.Length(); ++i) {
-    const nsCString& keyValue = keyValues[i];
+  for (const auto& keyValue : aBlocklistEntry.Split('\t')) {
     nsTArray<nsCString> splitted;
     ParseString(keyValue, ':', splitted);
     if (splitted.Length() != 2) {
       // If we don't recognize the input data, we do not want to proceed.
       gfxCriticalErrorOnce(CriticalLog::DefaultOptions(false))
-          << "Unrecognized data " << keyValue.get();
+          << "Unrecognized data " << nsCString(keyValue).get();
       return false;
     }
     const nsCString& key = splitted[0];